Hydrocracking shale oil



l. KlRslENBAUM ETA. `2,884,371

HYDROCRACKING SHALE OIL April 28,1959 l n v ll Filed neo. zo,v 1954:sinon x/nsHENAuu KENNETH n. may

l. KIRSHENBAUM ETAL 2,884,371

HYDROCRACKING SHALE OIL I I April 28, 195.9

2 Sheets-Sheet 2 Filed De. 30, 19.54

Ill'

lslooR xmsnfnsnuu KENNETH n. muur ,INVENTORS Hfr J. 00%

United States Patent O HYDROCRACKING SHALE OIL Isidor Kirshenbaum,Union, Kenneth K. Kearby, Watchung, and Henry J. Ogorzaly, Summit, N .Jassignors to Esso Research and Engineering Company, a corporation ofDelaware Application December 30, 1954, Serial No. 478,682

1o claims. (c1. 20s-'111) The present invention relates to theconversion of higher boiling hydrocarbons to lower boiling hydrocarbonsand more particularly relates to hydrocracking of shale oil to producehigh yields of olenic and aromatic gasolines of high octane number andlow sulfur content.

Raw shale oil is obtained by retorting oil shale and oontainshydrocarbons and organic material consisting of hydrocarbons incombination with sulfur, nitro-gen and oxygen. The shale oil has anextremely high content of nitrogen compounds which distinguishes it fromcrude petroleum oil. Various refining procedures have *been suggestedfor oil shale or various fractions separated from shale oil.Conventional methods of refining or conversion are not applicable to thecatalytic cracking of raw shale oil. Carbon or coke formation isexcessive, presumably because of the nitrogen, sulfur and/or oxygencompounds present in the raw shale oil. In addition, the gasolineproduct'contains an excessive amount of sulfur and needs furtherrefining. In order to eliminate these undesirable compounds and preparea stock suitable for cracking or further refining, it has been feltnecessary to resort to coking or hydro-genation of the shale oil.Hydrogenation is an expensive process and accordingly this method fofprocessing shale oil is not competitive with processing of cmdepetroleum oil because it requires excessive amounts of hydrogen.

It has now been found that raw shale oil can be cracked directly overcracking catalysts containing an added hydrogenation component such asmolybdenum oxide, platinum, etc. The cracking is carried out in thepresence of hydrogen, under a pressure between about 100 `and 700p.s.i.g., preferably 200-500 (pounds per square inch gage) and at atemperature between about 950 and ll00 F. The amount of hydrogenintroduced into the cracking zone is between about 2,000 cu. ft. and10,000 cu. ft., preferably 3,500-6,000 cu. ft. (measured at standardatmospheric pressure and temperature) per barrel of shale oil feed.Hydrogen is consumed during the reaction and therefore hydrogen must besupplied to the reaction from an external source of a hydrogen-rich gas.In one form of the invention the extraneous hydrogen is obtained from ahydroforming unit operated in conjunction with the hydrocracking unit,'but extraneous hydrogen from any other source may be used. In anotherform of the invention the hydrocracking process is used in combinationwith a catalytic cracking process and in this case the hydrocrackingprocess lowers the nitrogen and sulfur contents of the shale yoil andproduces an improved shale oil feed for catalytic cracking.

A catalyst which is particularly effective in the present hydrocrackingprocess consists of a conventional cracking catalyst such as asilica-alumina catalyst containing about 87% silica and 13% alumina, towhich is added from about 8 to 16%, preferably around 10 to 12% 'byweight, based on the total catalyst composition, of molybdenum PatentedApr. 28, 1959y ice oxide. Other silica containing cracking catalystssuch as silica-magnesia, silica-alumina magnesia, silica-aluminazirconiaetc. may be used as the cracking catalyst base; Although the molybdenumoxide ycatalyst is preferred for the treatment of shale oil, under someconditions, platinum may be used as the hydrogenation component in whichlcase about 0.1 to 5% by weight of the total catalyst composition isplatinum, preferably 0.5-1 wt. percent. Instead of using freshsilica-alumina cracking catalyst, used catalyst removed from acommercial catalytic cra-cking unit may be used.

With the present process the raw shale oil is simultaneously cracked andhydrogenated to give a high yield of high octane number motor fuel. Atthe same time a small amount of coke or carbonaceous material isproduced which is much less than the amount of coke produced iby otherprocesses.

In addition to producing less carbon or coke than conventional catalyticcracking of the same kind of feed stock, the process of the presentinvention produces significantly more C-land C5+ gasoline of high octanenumber.

The molybdenum yoxide or other hydrogenation component may be added tothe silica-alumina base or support by merely mixing the dry ingedientstogether or by impregnating the silica-alumina catalyst or support withammonium molybdate and drying and calcining. Or the molybdenum oxide maybe sublimed to coat or be deposited on the cracking catalyst. The amountof the silicaalumina catalyst component may vary between about 84 and 92parts `by weight of the total catalyst so that there will be betweenabout 8 and 16 parts by weight of the molybdenum oxide or itsequivalent.

The process may be carried out using the uid solids technique but fixedbed and moving `bed catalysts or other lconventional types may be used.

In the drawings:

Fig. 1 represents a system including a hydrocracking unit and ahydroforming unit; and

Fig. 2 represents another system including a hydrocracking unit and acatalytic cracking unit.

Referring now to Fig. l of the drawings, the reference character 10designates a hydrocracking unit into which raw shale oil to be crackedis introduced through line 12. Also introduced into the hydrocracking-unit 10 is a hydrogen-rich gas introduced through line 14. In thehydrocracking unit the shale oil is heated to a temperature of about 950to 1l00 F., preferably between about 1035 `and 1060 F. The pressure inthe hydrocracking unit 10 is maintained between about 100 and 700p.s.i.g. pressure, preferably about 200 to 500 p.s.i.g. Thehydrogen-rich gas supplied through line 14 is introduced at the rate ofpreferably about 3500 to 6000 cubic feet of hydrogen per barrel of shaleoil feed to the hydrocracking unit 10. The catalyst in the hydrocrackingunit 10 comprises about of a silica-alumina cracking catalyst basecontaining about 13% alumina and about 10% molybdenum oxide. In thehydrocracking process hydrogen is consumed and it is therefore necessaryto supply hydrogen to the process. Part of the hydrogen is recoveredfrom the gaseous products of hydrocracking and the rest of the hydrogenis supplied from an external source. In the particular combination shownin Fig. 1 excess hydrogen from a hydroforming unit is supplied to thehydrocracking step. .The hydrogen from any external source is suppliedto the line 14 through line 15.

The hot hydrocracked vaporous products are with-l drawn overhead fromthe hydrocracking unit 10 and passed through line 16 to a fractionatingtower 18 for separating the hydrocracked products into desiredfractions. The gaseous fraction is taken overhead from the fractionatingtower through line 22 and all or a portion of this gas is passed throughline 24 and line 26 to an adsorption unit 28 for removing hydrocarbongases and providing a hydrogen-rich gas. The tail gas in line 22contains up to about 50% Cl-Ca hydrocarbons with the rest beinghydrogen. The amount of 'hydrogen in the tail gas depends upon the HZdilution introduced with the recycle gas and upon the severity ofoperation. With a 5000 c.f. Hz/bbl. of shale oil recycle rate andcracking to about a 70% conversion, the tail gas contains about 55% H2.The hydrogen-rich gas is withdrawn from the adsorption unit through line32 and recycled to the line 14 for introduction into the hydrocrackingunit. In some cases, especially when hyd-rocracking mildly, the gaseousproducts passing through line 24 may be directly recycled in whole orpart to thev hydrocracking unit 1,0 through line 34. 'lfhe adsorptionunity may utilize the iluid char adsorption process, an oil absorptionprocess or low temperature fractionation or any other well knownseparation process. The adsorption process is conventional and nofurther detailed description is considered necessary. The main purposeof the adsorption unit is to concentrate hydrogen in the gas to berecycled.

Another portion of the gas from line 22 may be passed through line 36and withdrawn from the system through line 38 and used las a source ofhydrogen, as for example in the hydrogenation of residual fuels,catalytically cracked stocks, etc. Returning to the fractionating tower18 any number of side streams may be withdrawn and in the drawing thereare shown three withdrawal lines. A light fraction is withdrawn throughtop line 42 and consists primarily of C4 hydrocarbons with a little C3and C hydrocarbon. The middle withdrawal line 44 comprises the C5 to 430F. motor fuel fraction and this fraction is withdrawn as product throughline 46. lf de sired, a portion or fraction of this motor fuel fractionmay ybe recycled through line 48 to a hydroforming unit 50 to be`described hereinafter.

The lower withdrawal line 52 contains hydrocarbons higher boiling thanthe motor fuel fraction and this fraction may be withdrawn from thesystem through line 54 or all or part of this fraction may be recycledthrough line 56 to the feed line 12 for recycle cracking in thehydrocracking unit 10. A bottoms fraction boiling above about 800 or 900F. is withdrawn from the bottom of the tower 18 through line 58.

Turning now to the hydroforming unit 50, line 62 comprises a feed linefor introducing a virgin naphtha boiling between about 200 and 430 F.preferably 22S-380 F. The hydroforming unit 50 is maintained under apressure of about 100-750 l-bs. per square inch gauge, temperature ofabout 750-l050 F. and about 2,000 to 10,000 cubic feet of hydrogenrecycle gas are used per barrel of oil. The hydrogen-rich gas isintroduced into the hydroforming unit 50 through line 64. Thehydroformed products in vapor form pass overhead from the hydroformingunit 50 through line 66 and are introduced into a second fractionatingtower 68 for fractionating the hydroformed products into desiredfractions. The separated gaseous fraction passes overhead through line72. The tail gas in line 72 normally contains less than about 40% C1-C3hydrocarbons with the rest being hydrogen. A portion of this gas isrecycled to the hydroforming unit 50 through lines 74 and 64.

During the hydroforming reaction there is a net pro duction of hydrogenand some of this excess hydrogen in the gaseous product withdrawnoverhead from the tower 68 is passed through line 76 and line 78 fo-rrecycle to the hydrocracking unit through lines 80vanl 32. If it isdesired to concentrate further the hydrogen in this gaseous stream thegas from line 78 may be passed through line 82 into the adsorption unit28 and the more concentrated hydrogen-containing gas withdrawn throughline 32 for passage to the hydrocracking unit It). The gaseoushydrocarbons removed from the hydrogen in the adsorption unit 28 arewithdrawn overhead from the adsorption unit 28 thro-ugh line 84. Aportion of the gaseous stream from line 76 may be withdrawn fro-m thesystem through line 86.

The hydroforming reaction in the hydroforming unit 50 can be carried outin the presence of any well known hydroforming catalyst such asalumina-molybdena, alumina-chromia, or alumina-platinum type catalysts.During the hydroforming reaction some carbon or coke may be deposited onthe catalyst yand in a iluid solids type process or in a moving bedprocess the partially spent or coked catalyst is withdrawn from thehydroforming unit 50 through line 88 and passed to a stripping zone 90where the catalyst is treated with an inert gas such as recycle gas, uegas or steam for removing volatilizable and/or entrained hydrocarbons.The stripped vapors may ybypass the regenerator through line 91 and whensteam stripping is used, stripped hydrocarbons may be separated from thecondensate and recovered. lf recycle gas is used for Stripping it may bereturned to the reactor 50. Tail gas from the hydrocracker l0 ordesorbed gases leaving unit 28 through 84 may be use-d for stripping.The stripped catalyst is passed through a line 92 to a regenerator 94into which air or other oxidizing gas is introduced through line 96. Thecombustion gases are passed overhead through line 98. The temperatureduring regeneration is between about 900 and 1200 F.

The hot regenerated catalyst is withdrawn from the regenerator throughline 102 and passed to a stripping and pretreating zone 104 where thecatalyst may be treated with a hydrogen-containing gas at a temperaturebetween about 800 and 1000 F. to remove any retained combustion gasesand also to reduce the valence of the molybdenum component on thecatalyst. During regeneration the molybdenum oxide is believed to beoxidized to a different form which is not as active as the partiallyreduced molybdenum oxide and the treatment and stripping in treatingzone 104 reduces the molybdenum compound to the active Valence state. Asthe hydrogen-containing gas for treatment in the stripping orpretreating zone 104, a part of the overhead gases from the firstfractionating tower 18 may `be used. A part of the gas from line 36 maybe passed through line 106 and used as the treating gas in zone 104. Thehot regenerate t catalyst is withdrawn from the stripping zone 104- andreturned to the hydroforming unit 50 through line 08.

Returning to the second fractionating tower 68 there arc shown threeside stream withdrawal lines but any number of such streams may bewithdrawn. The top 'withdrawal line is used for withdrawing C3 and C.1hydrocarbons. The second withdrawal line 11.2 is used for withdrawing aC5-430 F. motor fuel fraction. The bottom withdrawal line 114 may beused to withdraw a hydrocarbon fraction boiling above the gasoline ormotor fuel boiling range and having an end boiling point below about 600F. The motor fuell from h ydrocracking line 46 and the motor fuel fromhydroforming line 13.2 may be utilized separately, or they are blendedto form a high octane gasoline of low sulfur content. Elending of theltwo gasolines gives a more balanced fuel containing both aromatics andoleins.

The bottoms from the fractionating tower 68 containing the higherboiling polymers boiling above 430 F. are withdrawn from the bottom ofthe tower 68 through line 116 and may be withdrawn from the syste n,through line 118 but are preferably recycled to the feed line 12 forhydrocracking inthe hydrocracking unit l0. The products fromA line 114may be combined with this s reatr. (line 116), if they are not used forspecial purposes, for example, as aromatic solvents.

The motor fuel prouced by hydrocraclting raw shale oil is more olenicthan that produced by hydroforming naphtha and to adjust theolefin-aromatic ratio of the motor fuel obtained by blending hydroformedproduct (line 112) and hydrocracked motor fuel (46), a portion of thehydrocracked motor fuel from line 44 may be recycled to hydroformer feedline 62 through line 48 as part of the feed to hydroformer reactor 50.This reduces the olefin content and increases the leaded motor octanenumber obtainable at a given Research Motor Octane Number. This is ofadvantage when the gasoline is used in engines having compression ratiosof about 8 or higher.

During hydrocracking in the hydrocracking unit 10 coke or carbonaceousmaterial is deposited on the catalyst and it is necessary to regeneratethe catalyst. In a uid solids system the catalyst is withdrawn from thehydrocracking unit, stripped with steam or other inert gas to removevolatile hydrocarbons and the stripped catalyst is then renegerated in aregeneration zone (not shown in the drawing but similar to vessel 94) byair or other oxygen-containing gas. The temperature during regenerationis between about 900 and 1200 F. Following regeneration the catalyst maybe then pretreated with a hydrogen-containing gas similar to thetreatment given to the hydroforming catalyst in zone 104 and theso-treated regenerated catalyst is then returned to the hydrocrackingunit 10. In either case the pretreating step is optional and with somefeedstocks may be omitted.

Referring now to Fig. 2 of the drawings, the reference character 130designates a hydrocracking unit into which the raw shale oil isintroduced through line 132. Hydrogen-rich gas is `introduced into thehydrocracking unit 130 through line 134. Line 136 is used forintroducing extraneous hydrogen to line 134 and hydrocracking unit 130.The catalyst in the hydrocracking unit is the same type of catalystdescribed in connection with the hydrocracking unit 10 in Fig. l andpreferably comprises about .0

90% of a silica-alumina cracking catalyst base and 10% of molybdenumoxide.

In Fig. 2 the hydrocracking unit is used to modify the characteristicsof the raw shale oil and to prepare a clean gas oil feedstock for thecatalytic cracking unit 138. As above pointed out the raw shale oilcontains nitrogen, sulfur and oxygen compounds which are deleterious tocracking catalysts. Further, if raw shale oil were used as a feed forcatalytic cracking the gasoline produced would contain excessive amountsof sulfur and further treatment of the gasoline would be required tomake an acceptable product.

The pressure in the hydrocracking unit 130 is maintained between about100 and 700 p.s.i.g., the temperature is maintained between about 950and 1100 F. and the amount of hydrogen used is about 2,000 to 10,000cubic feet per barrel of shale oil fed to the hydrocracking unit 130.Feed rates are suflciently high to maintain mild hydrocrackingconditions and to maximize the yield of product boiling above 430 F.

The vaporous hydrocracked products are passed overhead through line 140to a fractionating tower 142 for separating the cracked products intodesired fractions. The gaseous fraction is taken overhead through line144 and may be recycled in whole or in part through line 146 and line148 to hydrogen inlet line 134 to the hydrocracking unit. In cases wherethere is no net production of hydrogen, the gaseous overhead stream ispassed through line 150 to an adsorption unit 152 for removinghydrocarbons from the gaseous stream and to produce a hydrogen-richstream which is withdrawn through line 154 and recycled through line 148and line 134 to the hydrocracking unit 130. The separated hydrocarbongases are removed from the adsorption unit through line 156. If desired,a portion of the gaseous stream passing through line 144 may bewithdrawn from the system through line 158.

Returning now to the fractionating tower 142 the cracked products arefractionated and a lighter fraction comprising relatively light (C4 andlower) hydrocarbons is withdrawn through top withdrawal line 160. Amotor fuel fraction comprising a C5-430 F. motor fuel is withdrawnthrough the bottom withdrawal line 162. Bottoms from the fractionatingtower 142 are withdrawn through line 164 and all or a part thereofpassed through line 166 as feed to the catalytic cracking unit 138. Thisbottoms fraction has an initial boiling point of about 430 F. and amid-boiling point of about 600-700 F. Another portion of the bottomsfrom line 164 may be recycled to the hydrocracking unit through line168. In some cases a portion of the shale oil feed from line 132 may bepassed through line 170 to feed line 166 to the catalytic cracking unit138.

The catalytic cracking unit 138 represents a conventional catalyticcracking unit utilizing silica-alumina catalyst which may besynthetically prepared or which may comprise acid treated bentoniticclays. The temperature during cracking is maintained between about 850and 1000 F. The cracked products are taken overhead through line 172 andpassed to a second fractionating tower 174 where the cracked productsare separated into desired fractions. A gaseous fraction is takenoverhead through line 176 and a C4430 F. motor fuel fraction iswithdrawn through top withdrawal line 178. A cycle oil fraction boilingabove the motor fuel range is withdrawn through lower withdrawal line180 and a portion of this stream may be withdrawn from the systemthrough line 182. If desired, a portion of this cycle oil from line 180may be recycled through line 184 to feed line 132 for recycling to thehydrocracking unit 130. This results in an overall smaller production ofcoke. The bottoms fraction from tower 174 is withdrawn through line 186and all or a portion of this bottoms fraction can be removed from thesystem through line 188. If desired, a portion of the bottoms fractionfrom line 186 may be recycled through line 190 to the cata- .lyticcracking unit 138 and/or another portion of the bottoms fraction passedthrough line 192 is preferably recycled to line 132 as feed to thehydrocracking unit 130 to reduce coke formation.

The motor fuel from catalytic cracking (line 178) and the motor fuelfrom hydrocracking (line 162) may be separately utilized, but preferablythe two motor fuels are blended to form a high octane number gasoline oflow sulfur content. When the hydrocracking unit is operated atconditions of mild severity blending balances the octane number of thetwo products.

Shale oil (designated NTU shale oil) produced from Colorado shale in agas combustion pilot plant retort of the Bureau of Mines has thefollowing physical properties:

Gravity, API, 60 F. 19.0 Pour, F. 75.0 Vis. SUS, 130 F. 153 Vis. SUS,210 F. 51

The analysis of the shale oil was as follows:

Total sulfur, wt. percent 0.74 Nitrogen, wt. percent 2.06

The shale oil also contained tar acids and tar bases. The following isthe ASTM distillation:

F. I.B.P. 390 5 volume percent 486 50 volume percent 686 (J-430 F.Gasoline:

Research Octane No 89.5. 40.4 Vol. percent. 25.2 Vol. percent.

730 cubic feet per barrel of oil.

Aromatics Olefms Sulfur, by weight Hydrogen consumption Thus the shaleoil was cracked to C54- gasoline with a 45.5 weight percent selectivityand to C44- gasoline with a 55.1 weight percent selectivity. Theselectivity to carbon was 5.4%. The gasoline produced had a 42.4 F.aniline point and a 50.3 API gravity.

The following comparison with other processes is given to show theimproved results obtained with the present invention. From these data itwill be apparent that the process of the present invention produceshigher yields of `gasoline of high octane number and low sulfur with theproduction of less coke and less consumption of ing unit 10 for furtherprocessing. Some of the tail gas from the hydroformer 50 which containsabout 67% hydrogen is blended with some of the tail gas from thehydrocracker 10 containing about 51% hydrogen. This mixed stream is fedto the char adsorber 28 to produce gas containing about 78% H2. Thisstream from adsorber 28 is mixed in line 34 or in the hydrocracking unit10 with additional hydrocracker tail gas containing 5% H2 to give the83.5 million cu. ft'. of hydrocracker recycle gas containing 50 millioncu. ft. of H2. This recycle gas is fed through line 14 with the shaleoil into the hydrocracker 10. Part of the hydrocracker tail gas is fedvia lines 36 and 106 to the stripping and/or pretreating section (104and others not shown) of the various units.

The hydroforming reaction can be carried out under pressures betweenabout 100 and 700 p.s.i.g., at a temperature between about 750 and l050F. and in the presence of about 2,000 to 10,000 cubic feet ofhydrogenrich recycle gas per barrel of feed. The hydrocracking reactioncan be carried out at a pressure between about 100 and 700 p.s.i.g. at atemperature of about 950 and 1100 F. and in the presence preferably ofabout 3,500 to 10,000 cubic feet of hydrogen rich recycle gas per barrelof feed. The adsorption process using activated carbon or an alkali oralkaline earth metal aluminum silicate molecular sieve type adsorbentmay be carried out at a pressure between 100 and 500 p.s.i.g. orgreater, an adsorption temperature at the feed plate between about 100and 200 F. and utilizing between about 0.15 and 1.0 lbs.

hydrogen. of adsorbent per cubic foot of tail gas.

Conversion, Wt. Yields, Wt.

Percent H2 Con- Percent Percent Process Feed sumcd, S in s.c.f./b.Gasoline 430 F. 400 F. CH- Carbon Gasoline Hydrocracking of thisinvention Raw shale oil.. 74 730 1 43 4 0. 16 Raw shale oil.- 60 14Catalytic Cracking Raw shale oil.. 23 0. 48 Hydrogenated shale oil 60 l?Recycle Coking Raw shale oil 14 ff-S 1 Research O.N.=89.5. 2 ResearchO.N.=90. 1 Research O.N.=65.

One example for carrying out a process according to Fig. l is asfollows: Hydroformer- Catalyst: 90Al2O3-10M0O3 Feed: 20,000 bbls./day ofa 225 430 F. naphtha Recycle: 89 million cu. ft./day of recycle gascontaining 67% H2 Product:

16,000 bbls./day of C4430 F. gasoline (98 Res. O.N.) 28 million cu.ft./day of tail gas (67% H2) 300 bbls./day of 430 F.lpolymer Operatingpressure: 200 p.s.i.g. Hydrocracking unit- Catalyst:78SiO2-12Al2O3-10M0O3 Feed: 10,000 bbls./day of 686 F. midboiling pointshale oil Recycle: 83.5 million cu. ft./day of gas containing about 60%H2 Product: 4290 bbls. of C4-430 F. gasoline (90 Res.

O.N. clear) H2 consumption: 7.3 million cu. ft./day

Operating pressure: 500 p.s.i.g.

Fluid char adsorption unit- Operating conditions: 500 p.s.i.g.; 150 F.adsorption temp.; 0.3 lb. of char per cu. ft. of tail gas; 550 F.desorption temp.

Product: Enriched gas having an H2 content of about 78 mol percent Inthe operation of the process,l the 300 bbls. of 430 F.l polymer iscycled through line 116 to the hydrocrack- Varying the severity ofoperation of the hydrocracking and hydroforming units changes thehydrogen content of the tail gases from these units. In general, theless severe operations result in more hydrogen in the tail gases.

The shale oil feed contains nitrogen compounds and some of thesenitrogen compounds or decomposition products thereof are carried overwith the distillate fractions. The nitrogen compounds may be removedfrom the distillates by solvent extraction or other extraction processesto recover valuable chemicals. For example, amines of various types arepresent and these can be recovered by extraction with dilute acids or bysuitable solvents or solid adsorbents.

What is claimed is:

l. A process for converting shale oil containing sulfur and nitrogencompounds as impurities to motor fuel of high octane number in theregion of with low carbon production which comprises contacting shaleoil with a single solid catalyst consisting of silica-alumina crackingcatalyst containing about 8-16% by weight of the total catalyst ofmolybdenum oxide at a temperature between about 950 F. and 1100 F.,under a pressure between about and 700 p.s.i.g. and in the presence of ahydrogen rich gas in an amount between about 2000 and 10,000 cubic feetper barrel of shale oil.

2. A process according to claim 1 wherein the amount of molybdenum oxideis 10% by weight.

3. A process according to claim 2 wherein the ternperature is about1050`F., the pressure is about 500 p.s.i.g., and the amount of hydrogenrich gas is about 5000 cubic feet per barrel of shale oil.

4. A process according to claim 1 wherein the silicaalumina crackingcatalyst contains about 78% of silica and 12% of alumina and the highoctane motor fuel contains low sulfur and easily removable compounds.

5. A process according to claim 1 wherein the products from theconversion step are fractionated into a motor fuel fraction and a gasand hydrogen is consumed during the conversion step, said gas is treatedto produce a hydrogen-rich gas, said hydrogen-rich gas is recycled tosaid conversion step and hydrogen-rich gas is supplied from anextraneous source.

6. A process for hydrocracking raw shale oil to produce motor fuel whichcomprises feeding a raw shale oil to a hydrocracking reactor for contactwith a single solid catalyst consisting of a silica-alumina crackingcatalyst containing about by weight of molybdenum oxide, said reactorbeing maintained at a temperature between about 950 and 1100J F., and ata pressure between about 100 and 700 p.s.i.g., introducing hydrogen intosaid reactor at a rate between about 2000 and 10,000 cubic feet perbarrel of shale oil and consuming hydrogen during the hydrocrackingstep, recovering motor fuel from the hydrocracked products,simultaneously subjecting naphtha to a catalytic hydroforming operationunder conditions to have a net production of hydrogen, utilizing some ofthe hydrogen from the hydroforming operation to supply hydrogen for thehydrocracking step, and recovering reformed naphtha from the hydroformedproducts.

v7. A process according to claim 6 wherein the hydrocracked products areseparated into a liquid fraction and a gaseous fraction, the gaseousfraction is treated to increase the hydrogen content thereof and theso-treated hydrogen-rich gaseous fraction is recycled to saidhydrocracking reactor.

8. A process for converting raw shale oil to motor fuel of high octanenumber and with low production of coke, which comprises feeding such rawshale oil to a hydrocracking reactor containing a silica-aluminacracking catalyst modified by the addition of about 10% of molybdenumoxide, under superatmospheric pressure between about and 700 p.s.i.g.,at a cracking temperature between about 950 F. and 1100 F. and in thepresence of atleast 2000 cubic feet of hydrogen per barrel of shale oil,removing hydrocracked products from said reactor, separating gas from amotor fuel fraction having a high octane number and a fraction higherboiling than the motor fuel fraction, passing said higher boilingfraction to a catalytic cracking unit, recovering an additional amountof motor fuel and a gas oil cycle fraction from the catalyticallycracked products and recycling at least part of said gas oil cyclefraction to said hydrocracking reactor.

9. A process according to claim 6 wherein the hydrocracked motor fueland reformed naphtha are blended to form a high octane gasoline.

10. A process according to claim 6 wherein the hydrocracked motor fuelis olenic and is at least in part passed to said hydroforming step toreduce the olen content and to increase the octane number of the motorfuel.

References Cited in the file of this patent UNITED STATES PATENTS2,093,843 McKee Sept. 21, 1937 2,106,013 Ocon Ian. 18, 1938 2,191,157Pier et al Feb. 20, 1940 2,304,183 Layng et al Dec. 8, 1942 2,312,445Ruthrutf Mar. 2, 1943 2,341,792 Kanhofer Feb. 15, 1944 2,619,450 FlemingNov. 25, 1952 2,694,035 Smith et al Nov. 9, 1954 2,697,681 Murray et alDec. 21, 1954 2,703,308 Oblad et a1 Mar. 1, 1955 2,708,180 Fuener et alMay 10, 1955 2,727,853 Hennig Dec. 20, 1955 2,758,958 Anhorn et al Aug.14, 1956 2,767,121 Watkins Oct. 16, 1956 OTHER REFERENCES Smith et al.:Ind. and Eng. Chem., vol. 44 (1952), pages 586-589.

1. A PROCESS FOR CONVERTING SHALE OIL CONTAINING SULFUR AND NITROGENCOMPOUNDS AS IMQURITIES TO MOTOR FUEL OF HIGH OCTANE NUMBER IN THEREGION OF 90 WITH LOW CARBON PRODUCTION WHICH COMPRISES CONTACTING SHALEOIL WITH A SINGLE SOLID CATALYST CONSISTING OF SILICA-ALUMINA CRACKINGCATALYST CONTAINING ABOUT 8-1L% BY WEIGHT OF THE TOTAL CATALYST OFMOLYBDENUM OXIDE AT A TEMPERATURE BETWEEN ABOUT 950*F. AND 1100*F.,UNDER A PRESSURE BETWEEN ABOUT 100 AND 700 P.S.I.G. AND IN THE PRESENCEOF A HYDROGEN RICH GAS IN AN AMOUNT BETWEEN ABOUT 2000 AND 10,000 CUBICFEET PER BARREL OF SHALE OIL.